Welding Neck Flange
Weld Neck Flange features a neck extension and weld bevel. Provides a natural form connection ideal for larger, high-pressure applications.

Blind Flange
Blind Flange has no bore or inner diameter. They are often altered to include NPT threads or custom bore holes to function as hubless Slip On flanges.

Lap Joint Flange
Lap Joint Flanges are intended to saddle over a stub end fitting. They feature an extended hub and a machined radius at the base of the flat face.

Slip On Flange
Slip On Flange is designed to accept the pipe into the center/bore, allowing welding around the outer diameter of the pipe. 

Socket Weld Flange
Socket Weld types have a socket to insert pipe when space limitations make Weld Neck flanges difficult to use. 

Threaded Flange
Threaded Flanges contain a female NPT threaded center for connection to male threaded piping. These flanges are commonly implemented in reducing connections.

CLASS 150 According to ASTM A/SA-105; ANSI B16.5

Nominal 

Pipe 

Size 

Outside

Diam. of 

Flange (O) 

Thick. 

of 

Flange (C) 

Diam. 

of

Raised Face (R) 

Diam. 

of Hub 

at Base (X) 

Length 

thru Hub 

(Y) 

Min. 

Thread 

Length 

(T) 

Min. 

Counter 

Bore (Q) 

No. of 

Holes 

Diam. of 

Holes 

Diam. of 

Bolts 

Diam.

of Bolt 

Circle 

Approx. 

Weight

 (in Pounds) 

½ 

3.5

0.44

1.38

1.19

0.62

0.62

— 

4

0.62

0.5

2.38

1

¾ 

3.88

0.5

1.69

1.5

0.62

0.62

— 

4

0.62

0.5

2.75

2

1

4.25

0.56

2

1.94

0.69

0.69

— 

4

0.62

0.5

3.12

2

1 ¼ 

4.62

0.62

2.5

2.31

0.81

0.81

— 

4

0.62

0.5

3.5

3

1 ½ 

5

0.69

2.88

2.56

0.88

0.88

— 

4

0.62

0.5

3.88

3

2

6

0.75

3.62

3.06

1

1

— 

4

0.75

0.62

4.75

5

2 ½ 

7

0.88

4.12

3.56

1.12

1.12

— 

4

0.75

0.62

5.5

7

3

7.5

0.94

5

4.25

1.19

1.19

— 

4

0.75

0.62

6

8

3 ½ 

8.5

0.94

5.5

4.81

1.25

1.25

— 

8

0.75

0.62

7

11

4

9

0.94

6.19

5.31

1.31

1.31

— 

8

0.75

0.62

7.5

13

5

10

0.94

7.31

6.44

1.44

1.44

— 

8

0.88

0.75

8.5

15

6

11

1

8.5

7.56

1.56

1.56

— 

8

0.88

0.75

9.5

19

8

13.5

1.12

10.62

9.69

1.75

1.75

— 

8

0.88

0.75

11.75

30

10

16

1.19

12.75

12

1.94

1.94

— 

12

1

0.88

14.25

43

12

19

1.25

15

14.38

2.19

2.19

— 

12

1

0.88

17

64

14

21

1.38

16.25

15.75

2.25

2.25

— 

12

1.12

1

18.75

90

16

23.5

1.44

18.5

18

2.5

2.5

— 

16

1.12

1

21.25

98

18

25

1.56

21

19.88

2.69

2.69

— 

16

1.25

1.13

22.75

130

20

27.5

1.69

23

22

2.88

2.88

— 

20

1.25

1.12

25

165

24

32

1.88

27.25

26.12

3.25

3.25

— 

20

1.38

1.25

29.5

220

CLASS 300 According to ASTM A/SA-105; ANSI B16.5

Nominal 

Pipe 

Size  

Outside

Diam. of 

Flange (O)  

Thick. 

of 

Flange (C)  

Diam. 

of

Raised Face 

(R)

Diam. 

of Hub 

at Base 

(X)

Length 

thru Hub 

(Y) 

Min. 

Thread 

Length 

(T) 

Min. 

Counter Bore 

(Q) 

No. of 

Holes 

Diam. of 

Holes 

Diam.

of Bolts 

Diam.

of Bolt 

Circle 

Approx.

Weight 

(in Pounds) 

1/2

3.75

0.56

1.38

1.5

0.88

0.62

0.93

4

0.62

0.5

2.62

2

3/4

4.62

0.62

1.69

1.88

1

0.62

1.14

4

0.75

0.62

3.25

3

1

4.88

0.69

2

2.12

1.06

0.69

1.41

4

0.75

0.62

3.5

3

1 1/4

5.25

0.75

2.5

2.5

1.06

0.81

1.75

4

0.75

0.62

3.88

4

1 1/2

6.12

0.81

2.88

2.75

1.19

0.88

1.99

4

0.88

0.75

4.5

6

2

6.5

0.88

3.62

3.31

1.31

1.12

2.5

8

0.75

0.62

5

7

2 1/2

7.5

1

4.12

3.94

1.5

1.25

3

8

0.88

0.75

5.88

10

3

8.25

1.12

5

4.62

1.69

1.25

3.63

8

0.88

0.75

6.62

13

3 1/2

9

1.19

5.5

5.25

1.75

1.44

4.13

8

0.88

0.75

7.25

17

4

10

1.25

6.19

5.75

1.88

1.44

4.63

8

0.88

0.75

7.88

22

5

11

1.38

7.31

7

2

1.69

5.69

8

0.88

0.75

9.25

28

6

12.5

1.44

8.5

8.12

2.06

1.81

6.75

12

0.88

0.75

10.62

39

8

15

1.62

10.62

10.25

2.44

2

8.75

12

1

0.88

13

58

10

17.5

1.88

12.75

12.62

2.62

2.19

10.88

16

1.12

1

15.25

81

12

20.5

2

15

14.75

2.88

2.38

12.94

16

1.25

1.12

17.75

115

14

23

2.12

16.25

16.75

3

2.5

14.19

20

1.25

1.12

20.25

165

16

25.5

2.25

18.5

19

3.25

2.69

16.19

20

1.38

1.25

22.5

190

18

28

2.38

21

21

3.5

2.75

18.19

24

1.38

1.25

24.75

250

20

30.5

2.5

23

23.12

3.75

2.88

20.19

24

1.38

1.25

27

315

24

36

2.75

27.25

27.62

4.19

3.25

24.19

24

1.62

1.5

32

475

CLASS 600 According to ASTM A/SA-105; ANSI B16.5

Nominal 

Pipe 

Size  

Outside

Diam. of 

Flange (O)

Thick. 

of 

Flange 

(C)

Diam. 

of

Raised Face 

(R)

Diam. 

of Hub 

at Base (X)

Length 

thru Hub 

(Y) 

Min. 

Thread 

Length 

(T) 

Min. 

Counter 

Bore 

(Q) 

No. of 

Holes 

Diam. of 

Holes 

Diam. of 

Bolts 

Diam. of 

Bolt Circle 

Approx. 

Weight 

(in Pounds) 

1/2

3.75

0.56

1.38

1.5

0.88

0.62

0.93

4

0.62

0.5

2.62

2

3/4

4.62

0.62

1.69

1.88

1

0.62

1.14

4

0.75

0.62

3.25

3

1

4.88

0.69

2

2.12

1.06

0.69

1.41

4

0.75

0.62

3.5

4

1 1/4

5.25

0.81

2.5

2.5

1.12

0.81

1.75

4

0.75

0.62

3.88

5

1 1/2

6.12

0.88

2.88

2.75

1.25

0.88

1.99

4

0.88

0.75

4.5

7

2

6.5

1

3.62

3.31

1.44

1.12

2.5

8

0.75

0.62

5

9

2 1/2

7.5

1.12

4.12

3.94

1.62

1.25

3

8

0.88

0.75

5.88

13

3

8.25

1.25

5

4.62

1.81

1.38

3.63

8

0.88

0.75

6.62

16

3 1/2

9

1.38

5.5

5.25

1.94

1.56

4.13

8

1

0.88

7.25

21

4

10.75

1.5

6.19

6

2.12

1.62

4.63

8

1

0.88

8.5

37

5

13

1.75

7.31

7.44

2.38

1.88

5.69

8

1.12

1

10.5

63

6

14

1.88

8.5

8.75

2.62

2

6.75

12

1.12

1

11.5

80

8

16.5

2.19

10.62

10.75

3

2.25

8.75

12

1.25

1.12

13.75

115

10

20

2.5

12.75

13.5

3.38

2.56

10.88

16

1.38

1.25

17

170

12

22

2.62

15

15.75

3.62

2.75

12.94

20

1.38

1.25

19.25

200

14

23.75

2.75

16.25

17

3.69

2.88

14.19

20

1.5

1.38

20.75

230

16

27

3

18.5

19.5

4.19

3.06

16.19

20

1.62

1.5

23.75

330

18

29.25

3.25

21

21.5

4.62

3.12

18.19

20

1.75

1.63

25.75

400

20

32

3.5

23

24

5

3.25

20.19

24

1.75

1.62

28.5

510

24

37

4

27.25

28.25

5.5

3.62

24.19

24

2

1.88

33

730

CLASS 900According to ASTM A/SA-105; ANSI B16.5

Nominal 

Pipe 

Size 

Outside

Diam. of 

Flange (O)

Thick. 

of 

Flange 

(C)

Diam. 

of

Raised Face 

(R)

Diam. 

of Hub 

at Base 

(X)

Length 

thru Hub (Y) 

Min.

Thread 

Length 

(T) 

Min.

Counter 

Bore 

(Q) 

No. of

Holes 

Diam. of

Holes 

Diam. of

Bolts 

Diam. of

Bolt Circle 

Approx.

 Weight 

(in Pounds) 

1/2

4.75

0.88

1.38

1.5

1.25

0.88

0.93

4

0.88

0.75

3.25

4

3/4

5.12

1

1.69

1.75

1.38

1

1.14

4

0.88

0.75

3.5

5

1

5.88

1.12

2

2.06

1.62

1.12

1.41

4

1

0.88

4

8

1 1/4

6.25

1.12

2.5

2.5

1.62

1.19

1.75

4

1

0.88

4.38

9

1 1/2

7

1.25

2.88

2.75

1.75

1.25

1.99

4

1.12

1

4.88

12

2

8.5

1.5

3.62

4.12

2.25

1.5

2.5

8

1

0.88

6.5

25

2 1/2

9.62

1.62

4.12

4.88

2.5

1.88

3

8

1.12

1

7.5

36

3

9.5

1.5

5

5

2.12

1.62

3.63

8

1

0.88

7.5

26

4

11.5

1.75

6.19

6.25

2.75

1.88

4.63

8

1.25

1.12

9.25

53

5

13.75

2

7.31

7.5

3.12

2.12

5.69

8

1.38

1.25

11

83

6

15

2.19

8.5

9.25

3.38

2.25

6.75

12

1.25

1.12

12.5

110

8

18.5

2.5

10.62

11.75

4.00

2.50

8.75

12

1.5

1.38

15.5

170

10

21.5

2.75

12.75

14.5

4.25

2.81

10.88

16

1.5

1.38

18.5

245

12

24

3.12

15

16.5

4.62

3

12.94

20

1.5

1.38

21

325

14

25.25

3.38

16.25

17.75

5.12

3.25

14.19

20

1.62

1.5

22

400

16

27.75

3.5

18.5

20

5.25

3.38

16.19

20

1.75

1.63

24.25

425

18

31

4

21

22.25

6

3.5

18.19

20

2

1.88

27

600

20

33.75

4.25

23

24.5

6.25

3.62

20.19

20

2.12

2

29.5

730

24

41

5.5

27.25

29.5

8

4

24.19

20

2.62

2.5

35.5

1400

CLASS 1500 According to ASTM A/SA-105; ANSI B16.5

Nominal 

Pipe 

Size

Outside

Diam. of 

Flange (O)

Thick. 

of 

Flange 

(C) 

Diam. 

of

Raised Face 

(R)

Diam. 

of Hub 

at Base 

(X)

Length 

thru Hub 

(Y) 

Min. 

Thread 

Length 

(T) 

Min. 

Counter 

Bore 

(Q) 

No. of 

Holes 

Diam. of 

Holes 

Diam. of 

Bolts 

Diam. of 

Bolt Circle 

Approx. 

Weight 

(in Pounds) 

1/2

4.75

0.88

1.38

1.5

1.25

0.88

0.93

4

0.88

0.75

3.25

4

3/4

5.12

1

1.69

1.75

1.38

1

1.14

4

0.88

0.75

3.5

5

1

5.88

1.12

2

2.06

1.62

1.12

1.41

4

1

0.88

4

8

1 1/4

6.25

1.12

2.5

2.5

1.62

1.19

1.75

4

1

0.88

4.38

9

1 1/2

7

1.25

2.88

2.75

1.75

1.25

1.99

4

1.12

1

4.88

12

2

8.5

1.5

3.62

4.12

2.25

1.5

2.5

8

1

0.88

6.5

25

2 1/2

9.62

1.62

4.12

4.88

2.5

1.88

3

8

1.12

1

7.5

36

Standard

Specification

ASTM A105

Standard Specification for Carbon Steel Forgings for Piping Applications

ASTM A350

Standard Specification for Carbon and Low-Alloy Steel Forgings, Requiring Notch Toughness Testing for Piping Components

ASTM A182

Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service

ASTM A404

Specification for Forged or Rolled Alloy Steel Pip Flanges, Forged Fittings, and Valves and Parts Specially Heat Treated for High-Temperature Service (Withdrawn 1974)

ASTM A234

Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate and High Temperature Service

ASTM A420

Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Low-Temperature Service

ASTM A403

Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings

ASTM A694

Standard Specification for Carbon and Alloy Steel Forgings for Pipe Flanges, Fittings, Valves, and Parts for High-Pressure Transmission Service